These single station units are designed so that all you have to do is back your wheelchair up to the padded back rest and begin your work-out. These machines are fantastic for the shoulder and chest muscles. Because they do not require any hand holds, these are excellent units for Quads. All the work is done by placing your arm behind or under the pads, which work independently of each other and squeezing or lifting with your shoulder and chest muscles. Comes standard with 200 pound weight stack in 10 pound units. Smaller weight stacks available. The able bodied can also use these units.